Engine/Transmission (1994 - 1998) emissions test

[Berrigan]

I have the # 11 full forward and a 3 kgsk. My question is I will have to start going for an emission test this year as the truck is now 5 years old. My state uses the J1667 snap idle test. To pass the truck needs to have less than 30% opacity. They dont put the truck on a dyno they just idle it in neutral then snap the throttle to the floor, and let it rev until the computerized test device tells them to back out of the pedal. This happens after the gov has backed out. So the engine will rev to levels I would never take it to in idle.



I have it set to run clean and im not worried about to much opacity. I just dont want these guys taking my motor to 3500 plus rpm and holding it there. I really dont want to readjust the gsk either.



Does anyone know of a way to limit revs to maybe 3k with throttle adjustment or the like so these guys dont blow my motor. I just wanted full fueling to 31 or 3200 rpm and knew I would not take it above that level but these guys tell me they just put the pedal to the metal until something happens. They said part of the test is to ensure gov cut out operation.



Hey I want clean air to and will run my truck clean but how else can I deal with the rev issue. Thanks guys! Bill

 

[vssman]

Do you have any idea how the computer knows you've hit the gov? If it's solely based on putting it to the floor, then I'd limit the pedal travel so it doesn't go to full throttle.

 

[Berrigan]

VSSMAN



I dont think the emissions computer knows the rpm of the engine or even cares. I think (but not sure) it looks for the smoke puff on rpm rise ( change of throttle position) then looks to see the smoke improve at max rpm (whatever that turns out to be) . Then as long as either of those dont exceed 30% that run was a pass. Then the test is repeated 4 or 5 more times. Then all 6 tests are compaired to ensure consistancy. I think he said all tests have to be within a certain percent of each other. I also think its the test operators job to ensure the Tach hits redline and not above.



They consider the gov as part of the fuel system. If the gov doesnt gov you fail.



What does rpm have to do with emissions. Pass or fail me on smoke and dont exceed red line I said. (they said sorry thats the law)

 

[ronco]

I was thinking along the same lines as VSSMAN when I read his post. I would like to suggest a "collar" or "stopring" placed on your throttle cable to prevent WOT when the emissions operator does his thing. It could be as simple as cutting a piece of copper tubing to length and then cutting a slot lengthwise in the tubing to allow the piece to slip over the bare throttle cable. The length would determine how much travel you take away from the truck (I. E. the longer the length, the lower the R. P. M. ) The only way the emissions guy would know the governor was not preventing higher speed, is if he could tell the A/F mixture was not leaning out from lack of fuel. Just my . 02 cents.



Ronco

 

[Todd G]

I pass every year with plate full forward and 370 injectors.



They will ask you if you would like to run the test. Tell them you're an old pro at this and they'll let you do it. When the monitor says floor it, ease into the throttle a bit slower than slamming it to the floor. You can practice this on the way to the station. Tilt you right side mirror down so you can see the exhaust exit and you can be pretty good at limiting smoke. I figure I'll fail every time but since the retest is free I don't worry much.



I guess if all else fails, I'll slide the plate and AFC housing back. Or maybe just put a block under the go-peddle.